From 64e4745876e59cc94ca91f2877d0aa5683d1b08c Mon Sep 17 00:00:00 2001
From: Jules Wiriath <jules.wiriath@datadoghq.com>
Date: Tue, 21 Jul 2026 14:13:59 +0200
Subject: [PATCH 1/6] docs: fix libdatadog's behavior when 0 is passed

---
 crates/pipeline/src/lib.rs | 6 +++++-
 1 file changed, 5 insertions(+), 1 deletion(-)

diff --git a/crates/pipeline/src/lib.rs b/crates/pipeline/src/lib.rs
index eb25866e..7ad7ac95 100644
--- a/crates/pipeline/src/lib.rs
+++ b/crates/pipeline/src/lib.rs
@@ -379,7 +379,11 @@ impl WasmSpanState {
         Ok(())
     }
 
-    /// Enable telemetry on the lazily-built trace exporter.
+    /// Enable telemetry on the lazily-built trace exporter. Off by default —
+    /// dd-trace-js opts in from JS. `heartbeat_ms` sets the metric-flush cadence
+    /// (0 defers to libdatadog's default interval), `runtime_id`
+    /// tags telemetry payloads with the tracer's runtime id when provided, and
+    /// `debug_enabled` toggles libdd-telemetry's verbose logging.
     ///
     /// Must be called before the first `sendPreparedChunk`. Later calls have
     /// no effect.

From 81fb15d5fa2282373d02580d96dc343eb26751ef Mon Sep 17 00:00:00 2001
From: Jules Wiriath <jules.wiriath@datadoghq.com>
Date: Tue, 21 Jul 2026 14:19:38 +0200
Subject: [PATCH 2/6] chore: js tomfoolery

---
 crates/pipeline/src/lib.rs | 8 ++++----
 1 file changed, 4 insertions(+), 4 deletions(-)

diff --git a/crates/pipeline/src/lib.rs b/crates/pipeline/src/lib.rs
index 7ad7ac95..92bee1bc 100644
--- a/crates/pipeline/src/lib.rs
+++ b/crates/pipeline/src/lib.rs
@@ -380,10 +380,10 @@ impl WasmSpanState {
     }
 
     /// Enable telemetry on the lazily-built trace exporter. Off by default —
-    /// dd-trace-js opts in from JS. `heartbeat_ms` sets the metric-flush cadence
-    /// (0 defers to libdatadog's default interval), `runtime_id`
-    /// tags telemetry payloads with the tracer's runtime id when provided, and
-    /// `debug_enabled` toggles libdd-telemetry's verbose logging.
+    /// dd-trace-js opts in from JS. `heartbeat_ms`sets the metric-flush cadence
+    /// (0 defers to libdatadog's default interval), `runtime_id` tags telemetry
+    /// payloads with the tracer's runtime id when provided, and `debug_enabled`
+    /// toggles libdd-telemetry's verbose logging.
     ///
     /// Must be called before the first `sendPreparedChunk`. Later calls have
     /// no effect.

From 8e4d952f250271c411b031280c093120a8a4c1b9 Mon Sep 17 00:00:00 2001
From: Jules Wiriath <jules.wiriath@datadoghq.com>
Date: Mon, 27 Jul 2026 12:13:17 +0200
Subject: [PATCH 3/6] fix: comments

---
 crates/pipeline/src/lib.rs | 6 +-----
 1 file changed, 1 insertion(+), 5 deletions(-)

diff --git a/crates/pipeline/src/lib.rs b/crates/pipeline/src/lib.rs
index 92bee1bc..eb25866e 100644
--- a/crates/pipeline/src/lib.rs
+++ b/crates/pipeline/src/lib.rs
@@ -379,11 +379,7 @@ impl WasmSpanState {
         Ok(())
     }
 
-    /// Enable telemetry on the lazily-built trace exporter. Off by default —
-    /// dd-trace-js opts in from JS. `heartbeat_ms`sets the metric-flush cadence
-    /// (0 defers to libdatadog's default interval), `runtime_id` tags telemetry
-    /// payloads with the tracer's runtime id when provided, and `debug_enabled`
-    /// toggles libdd-telemetry's verbose logging.
+    /// Enable telemetry on the lazily-built trace exporter.
     ///
     /// Must be called before the first `sendPreparedChunk`. Later calls have
     /// no effect.

From 5db9485708bf71326f785c0cd145476bed26f759 Mon Sep 17 00:00:00 2001
From: Jules Wiriath <jules.wiriath@datadoghq.com>
Date: Fri, 24 Jul 2026 15:27:39 +0200
Subject: [PATCH 4/6] feat: use libdatadog's css instead of local one

---
 Cargo.lock                   | 108 ++++++++-----------
 crates/pipeline/Cargo.toml   |  18 ++--
 crates/pipeline/src/lib.rs   | 107 +++----------------
 crates/pipeline/src/stats.rs | 201 -----------------------------------
 test/pipeline.js             | 169 +----------------------------
 5 files changed, 70 insertions(+), 533 deletions(-)
 delete mode 100644 crates/pipeline/src/stats.rs

diff --git a/Cargo.lock b/Cargo.lock
index b69d0b47..0cda1f3b 100644
--- a/Cargo.lock
+++ b/Cargo.lock
@@ -917,7 +917,7 @@ dependencies = [
 [[package]]
 name = "libdd-capabilities"
 version = "2.1.0"
-source = "git+https://github.com/DataDog/libdatadog.git?rev=3081603d3c74f209be4e3be951f78a1a7469397f#3081603d3c74f209be4e3be951f78a1a7469397f"
+source = "git+https://github.com/DataDog/libdatadog.git?rev=15899dfe754d12186ce7db72f0ff41c1920d52ec#15899dfe754d12186ce7db72f0ff41c1920d52ec"
 dependencies = [
  "anyhow",
  "bytes",
@@ -941,7 +941,7 @@ dependencies = [
 [[package]]
 name = "libdd-capabilities-impl"
 version = "3.0.0"
-source = "git+https://github.com/DataDog/libdatadog.git?rev=3081603d3c74f209be4e3be951f78a1a7469397f#3081603d3c74f209be4e3be951f78a1a7469397f"
+source = "git+https://github.com/DataDog/libdatadog.git?rev=15899dfe754d12186ce7db72f0ff41c1920d52ec#15899dfe754d12186ce7db72f0ff41c1920d52ec"
 dependencies = [
  "anyhow",
  "bytes",
@@ -990,7 +990,7 @@ dependencies = [
 [[package]]
 name = "libdd-common"
 version = "5.1.0"
-source = "git+https://github.com/DataDog/libdatadog.git?rev=3081603d3c74f209be4e3be951f78a1a7469397f#3081603d3c74f209be4e3be951f78a1a7469397f"
+source = "git+https://github.com/DataDog/libdatadog.git?rev=15899dfe754d12186ce7db72f0ff41c1920d52ec#15899dfe754d12186ce7db72f0ff41c1920d52ec"
 dependencies = [
  "anyhow",
  "bytes",
@@ -1031,7 +1031,7 @@ dependencies = [
  "libc",
  "libdd-common 5.0.0",
  "libdd-libunwind-sys",
- "libdd-telemetry 5.0.1",
+ "libdd-telemetry",
  "nix 0.29.0",
  "num-derive",
  "num-traits",
@@ -1053,7 +1053,7 @@ dependencies = [
 [[package]]
 name = "libdd-data-pipeline"
 version = "7.0.0"
-source = "git+https://github.com/DataDog/libdatadog.git?rev=3081603d3c74f209be4e3be951f78a1a7469397f#3081603d3c74f209be4e3be951f78a1a7469397f"
+source = "git+https://github.com/DataDog/libdatadog.git?rev=15899dfe754d12186ce7db72f0ff41c1920d52ec#15899dfe754d12186ce7db72f0ff41c1920d52ec"
 dependencies = [
  "anyhow",
  "arc-swap",
@@ -1070,10 +1070,9 @@ dependencies = [
  "libdd-ddsketch 1.1.0",
  "libdd-dogstatsd-client",
  "libdd-shared-runtime 2.0.0",
- "libdd-telemetry 6.0.0",
  "libdd-tinybytes",
  "libdd-trace-normalization",
- "libdd-trace-protobuf 4.0.0 (git+https://github.com/DataDog/libdatadog.git?rev=3081603d3c74f209be4e3be951f78a1a7469397f)",
+ "libdd-trace-protobuf 4.0.0",
  "libdd-trace-stats",
  "libdd-trace-utils",
  "rmp-serde",
@@ -1098,7 +1097,7 @@ dependencies = [
 [[package]]
 name = "libdd-ddsketch"
 version = "1.1.0"
-source = "git+https://github.com/DataDog/libdatadog.git?rev=3081603d3c74f209be4e3be951f78a1a7469397f#3081603d3c74f209be4e3be951f78a1a7469397f"
+source = "git+https://github.com/DataDog/libdatadog.git?rev=15899dfe754d12186ce7db72f0ff41c1920d52ec#15899dfe754d12186ce7db72f0ff41c1920d52ec"
 dependencies = [
  "prost",
 ]
@@ -1106,24 +1105,41 @@ dependencies = [
 [[package]]
 name = "libdd-dogstatsd-client"
 version = "4.0.0"
-source = "git+https://github.com/DataDog/libdatadog.git?rev=3081603d3c74f209be4e3be951f78a1a7469397f#3081603d3c74f209be4e3be951f78a1a7469397f"
+source = "git+https://github.com/DataDog/libdatadog.git?rev=15899dfe754d12186ce7db72f0ff41c1920d52ec#15899dfe754d12186ce7db72f0ff41c1920d52ec"
 dependencies = [
  "anyhow",
+ "async-trait",
  "cadence",
  "http",
  "libdd-common 5.1.0",
+ "libdd-shared-runtime 2.0.0",
  "serde",
+ "tokio",
  "tracing",
 ]
 
 [[package]]
 name = "libdd-library-config"
-version = "3.0.0"
-source = "git+https://github.com/DataDog/libdatadog.git?rev=0c6e2a5df2a163d34c4f385353ffc5d7257c72f4#0c6e2a5df2a163d34c4f385353ffc5d7257c72f4"
+version = "1.0.0"
+source = "git+https://github.com/DataDog/libdatadog.git?rev=353134770b312b7ccd2df6afabc253090b948e5f#353134770b312b7ccd2df6afabc253090b948e5f"
+dependencies = [
+ "anyhow",
+ "memfd",
+ "rand",
+ "rmp",
+ "rmp-serde",
+ "serde",
+ "serde_yaml",
+]
+
+[[package]]
+name = "libdd-library-config"
+version = "2.0.0"
+source = "git+https://github.com/DataDog/libdatadog.git?rev=7cdeb7896e92d1ba38bde495934e112dac2eda25#7cdeb7896e92d1ba38bde495934e112dac2eda25"
 dependencies = [
  "anyhow",
  "libc",
- "libdd-trace-protobuf 4.0.0 (git+https://github.com/DataDog/libdatadog.git?rev=0c6e2a5df2a163d34c4f385353ffc5d7257c72f4)",
+ "libdd-trace-protobuf 3.0.2",
  "memfd",
  "prost",
  "rand",
@@ -1164,7 +1180,7 @@ dependencies = [
 [[package]]
 name = "libdd-shared-runtime"
 version = "2.0.0"
-source = "git+https://github.com/DataDog/libdatadog.git?rev=3081603d3c74f209be4e3be951f78a1a7469397f#3081603d3c74f209be4e3be951f78a1a7469397f"
+source = "git+https://github.com/DataDog/libdatadog.git?rev=15899dfe754d12186ce7db72f0ff41c1920d52ec#15899dfe754d12186ce7db72f0ff41c1920d52ec"
 dependencies = [
  "async-trait",
  "futures",
@@ -1205,39 +1221,10 @@ dependencies = [
  "winver",
 ]
 
-[[package]]
-name = "libdd-telemetry"
-version = "6.0.0"
-source = "git+https://github.com/DataDog/libdatadog.git?rev=3081603d3c74f209be4e3be951f78a1a7469397f#3081603d3c74f209be4e3be951f78a1a7469397f"
-dependencies = [
- "anyhow",
- "async-trait",
- "base64",
- "bytes",
- "futures",
- "getrandom 0.2.17",
- "hashbrown 0.15.5",
- "http",
- "libc",
- "libdd-capabilities 2.1.0",
- "libdd-common 5.1.0",
- "libdd-ddsketch 1.1.0",
- "libdd-shared-runtime 2.0.0",
- "serde",
- "serde_json",
- "sys-info",
- "tokio",
- "tokio-util",
- "tracing",
- "uuid",
- "web-time",
- "winver",
-]
-
 [[package]]
 name = "libdd-tinybytes"
 version = "1.1.1"
-source = "git+https://github.com/DataDog/libdatadog.git?rev=3081603d3c74f209be4e3be951f78a1a7469397f#3081603d3c74f209be4e3be951f78a1a7469397f"
+source = "git+https://github.com/DataDog/libdatadog.git?rev=15899dfe754d12186ce7db72f0ff41c1920d52ec#15899dfe754d12186ce7db72f0ff41c1920d52ec"
 dependencies = [
  "serde",
 ]
@@ -1245,21 +1232,21 @@ dependencies = [
 [[package]]
 name = "libdd-trace-normalization"
 version = "3.0.0"
-source = "git+https://github.com/DataDog/libdatadog.git?rev=3081603d3c74f209be4e3be951f78a1a7469397f#3081603d3c74f209be4e3be951f78a1a7469397f"
+source = "git+https://github.com/DataDog/libdatadog.git?rev=15899dfe754d12186ce7db72f0ff41c1920d52ec#15899dfe754d12186ce7db72f0ff41c1920d52ec"
 dependencies = [
  "anyhow",
- "libdd-trace-protobuf 4.0.0 (git+https://github.com/DataDog/libdatadog.git?rev=3081603d3c74f209be4e3be951f78a1a7469397f)",
+ "libdd-trace-protobuf 4.0.0",
 ]
 
 [[package]]
 name = "libdd-trace-obfuscation"
 version = "5.0.0"
-source = "git+https://github.com/DataDog/libdatadog.git?rev=3081603d3c74f209be4e3be951f78a1a7469397f#3081603d3c74f209be4e3be951f78a1a7469397f"
+source = "git+https://github.com/DataDog/libdatadog.git?rev=15899dfe754d12186ce7db72f0ff41c1920d52ec#15899dfe754d12186ce7db72f0ff41c1920d52ec"
 dependencies = [
  "anyhow",
  "fluent-uri",
  "libdd-common 5.1.0",
- "libdd-trace-protobuf 4.0.0 (git+https://github.com/DataDog/libdatadog.git?rev=3081603d3c74f209be4e3be951f78a1a7469397f)",
+ "libdd-trace-protobuf 4.0.0",
  "libdd-trace-utils",
  "log",
  "percent-encoding",
@@ -1269,8 +1256,8 @@ dependencies = [
 
 [[package]]
 name = "libdd-trace-protobuf"
-version = "4.0.0"
-source = "git+https://github.com/DataDog/libdatadog.git?rev=0c6e2a5df2a163d34c4f385353ffc5d7257c72f4#0c6e2a5df2a163d34c4f385353ffc5d7257c72f4"
+version = "3.0.2"
+source = "git+https://github.com/DataDog/libdatadog.git?rev=7cdeb7896e92d1ba38bde495934e112dac2eda25#7cdeb7896e92d1ba38bde495934e112dac2eda25"
 dependencies = [
  "prost",
  "serde",
@@ -1280,7 +1267,7 @@ dependencies = [
 [[package]]
 name = "libdd-trace-protobuf"
 version = "4.0.0"
-source = "git+https://github.com/DataDog/libdatadog.git?rev=3081603d3c74f209be4e3be951f78a1a7469397f#3081603d3c74f209be4e3be951f78a1a7469397f"
+source = "git+https://github.com/DataDog/libdatadog.git?rev=15899dfe754d12186ce7db72f0ff41c1920d52ec#15899dfe754d12186ce7db72f0ff41c1920d52ec"
 dependencies = [
  "prost",
  "serde",
@@ -1290,7 +1277,7 @@ dependencies = [
 [[package]]
 name = "libdd-trace-stats"
 version = "6.0.0"
-source = "git+https://github.com/DataDog/libdatadog.git?rev=3081603d3c74f209be4e3be951f78a1a7469397f#3081603d3c74f209be4e3be951f78a1a7469397f"
+source = "git+https://github.com/DataDog/libdatadog.git?rev=15899dfe754d12186ce7db72f0ff41c1920d52ec#15899dfe754d12186ce7db72f0ff41c1920d52ec"
 dependencies = [
  "anyhow",
  "arc-swap",
@@ -1304,9 +1291,8 @@ dependencies = [
  "libdd-ddsketch 1.1.0",
  "libdd-dogstatsd-client",
  "libdd-shared-runtime 2.0.0",
- "libdd-telemetry 6.0.0",
  "libdd-trace-obfuscation",
- "libdd-trace-protobuf 4.0.0 (git+https://github.com/DataDog/libdatadog.git?rev=3081603d3c74f209be4e3be951f78a1a7469397f)",
+ "libdd-trace-protobuf 4.0.0",
  "libdd-trace-utils",
  "rmp-serde",
  "serde",
@@ -1319,7 +1305,7 @@ dependencies = [
 [[package]]
 name = "libdd-trace-utils"
 version = "9.0.0"
-source = "git+https://github.com/DataDog/libdatadog.git?rev=3081603d3c74f209be4e3be951f78a1a7469397f#3081603d3c74f209be4e3be951f78a1a7469397f"
+source = "git+https://github.com/DataDog/libdatadog.git?rev=15899dfe754d12186ce7db72f0ff41c1920d52ec#15899dfe754d12186ce7db72f0ff41c1920d52ec"
 dependencies = [
  "anyhow",
  "base64",
@@ -1337,7 +1323,7 @@ dependencies = [
  "libdd-common 5.1.0",
  "libdd-tinybytes",
  "libdd-trace-normalization",
- "libdd-trace-protobuf 4.0.0 (git+https://github.com/DataDog/libdatadog.git?rev=3081603d3c74f209be4e3be951f78a1a7469397f)",
+ "libdd-trace-protobuf 4.0.0",
  "prost",
  "rand",
  "rmp",
@@ -1374,7 +1360,7 @@ version = "0.2.0"
 dependencies = [
  "anyhow",
  "getrandom 0.2.17",
- "libdd-library-config",
+ "libdd-library-config 1.0.0",
  "serde",
  "serde-wasm-bindgen",
  "wasm-bindgen",
@@ -1818,27 +1804,21 @@ checksum = "a89322df9ebe1c1578d689c92318e070967d1042b512afbe49518723f4e6d5cd"
 name = "pipeline"
 version = "0.1.0"
 dependencies = [
- "bytes",
  "console_error_panic_hook",
  "getrandom 0.2.17",
- "http",
  "js-sys",
  "libdatadog-nodejs-capabilities",
  "libdd-capabilities 2.1.0",
  "libdd-common 5.1.0",
  "libdd-data-pipeline",
  "libdd-shared-runtime 2.0.0",
- "libdd-trace-protobuf 4.0.0 (git+https://github.com/DataDog/libdatadog.git?rev=3081603d3c74f209be4e3be951f78a1a7469397f)",
- "libdd-trace-stats",
  "libdd-trace-utils",
- "rmp-serde",
  "serde",
  "serde_json",
  "uuid",
  "wasm-bindgen",
  "wasm-bindgen-futures",
  "wasm-bindgen-test",
- "web-time",
 ]
 
 [[package]]
@@ -1889,8 +1869,8 @@ name = "process-discovery"
 version = "0.1.0"
 dependencies = [
  "anyhow",
- "libdd-library-config",
- "libdd-trace-protobuf 4.0.0 (git+https://github.com/DataDog/libdatadog.git?rev=0c6e2a5df2a163d34c4f385353ffc5d7257c72f4)",
+ "libdd-library-config 2.0.0",
+ "libdd-trace-protobuf 3.0.2",
  "napi",
  "napi-derive",
 ]
diff --git a/crates/pipeline/Cargo.toml b/crates/pipeline/Cargo.toml
index 8056816e..81f1c15b 100644
--- a/crates/pipeline/Cargo.toml
+++ b/crates/pipeline/Cargo.toml
@@ -14,17 +14,13 @@ js-sys = "0.3"
 serde = { version = "1.0", features = ["derive"] }
 serde_json = "1"
 libdatadog-nodejs-capabilities = { path = "../capabilities" }
-libdd-capabilities = { git = "https://github.com/DataDog/libdatadog.git", rev = "3081603d3c74f209be4e3be951f78a1a7469397f" }
-libdd-common = { git = "https://github.com/DataDog/libdatadog.git", rev = "3081603d3c74f209be4e3be951f78a1a7469397f", default-features = false }
-libdd-data-pipeline = { git = "https://github.com/DataDog/libdatadog.git", rev = "3081603d3c74f209be4e3be951f78a1a7469397f", default-features = false, features = ["telemetry"] }
-libdd-trace-utils = { git = "https://github.com/DataDog/libdatadog.git", rev = "3081603d3c74f209be4e3be951f78a1a7469397f", default-features = false, features = ["change-buffer"] }
-libdd-trace-stats = { git = "https://github.com/DataDog/libdatadog.git", rev = "3081603d3c74f209be4e3be951f78a1a7469397f", default-features = false }
-libdd-trace-protobuf = { git = "https://github.com/DataDog/libdatadog.git", rev = "3081603d3c74f209be4e3be951f78a1a7469397f", default-features = false }
-libdd-shared-runtime = { git = "https://github.com/DataDog/libdatadog.git", rev = "3081603d3c74f209be4e3be951f78a1a7469397f", default-features = false }
-rmp-serde = "1"
-bytes = "1"
-http = "1"
-web-time = "1"
+# TODO: Replace these temporary libdatadog PR revs with the official release/tag
+# that contains DataDog/libdatadog#2235, then regenerate Cargo.lock.
+libdd-capabilities = { git = "https://github.com/DataDog/libdatadog.git", rev = "15899dfe754d12186ce7db72f0ff41c1920d52ec" }
+libdd-common = { git = "https://github.com/DataDog/libdatadog.git", rev = "15899dfe754d12186ce7db72f0ff41c1920d52ec", default-features = false }
+libdd-data-pipeline = { git = "https://github.com/DataDog/libdatadog.git", rev = "15899dfe754d12186ce7db72f0ff41c1920d52ec", default-features = false, features = ["telemetry"] }
+libdd-trace-utils = { git = "https://github.com/DataDog/libdatadog.git", rev = "15899dfe754d12186ce7db72f0ff41c1920d52ec", default-features = false, features = ["change-buffer"] }
+libdd-shared-runtime = { git = "https://github.com/DataDog/libdatadog.git", rev = "15899dfe754d12186ce7db72f0ff41c1920d52ec", default-features = false }
 console_error_panic_hook = "0.1"
 
 [target.'cfg(target_arch = "wasm32")'.dependencies]
diff --git a/crates/pipeline/src/lib.rs b/crates/pipeline/src/lib.rs
index eb25866e..1fb05c45 100644
--- a/crates/pipeline/src/lib.rs
+++ b/crates/pipeline/src/lib.rs
@@ -18,8 +18,6 @@ mod span_bytes;
 mod trace_data;
 use trace_data::*;
 
-mod stats;
-
 use libdd_trace_utils::change_buffer::{ChangeBuffer, ChangeBufferState};
 use libdd_trace_utils::span::v04::{AttributeAnyValue, AttributeArrayValue, SpanEvent};
 use span_string::SpanString;
@@ -170,7 +168,6 @@ pub struct WasmSpanState {
     exporter: UnsafeCell<Option<TraceExporter<WasmCapabilities, LocalRuntime>>>,
     builder: UnsafeCell<Option<TraceExporterBuilder<LocalRuntime>>>,
     cbs: RefCell<ChangeBufferState<WasmTraceData>>,
-    stats_collector: RefCell<Option<stats::StatsCollector>>,
     /// Chunks staged by `prepareChunk`, one per trace (segment), sent together by
     /// `sendPreparedChunk` as a single multi-trace request. The exporter groups a
     /// flush batch by trace and calls `prepareChunk` once per trace so each chunk
@@ -224,21 +221,6 @@ impl Drop for InFlightGuard<'_> {
     }
 }
 
-fn stats_flush_result(sent: bool, collapsed_spans: u64) -> Result<JsValue, JsValue> {
-    let result = js_sys::Object::new();
-    js_sys::Reflect::set(
-        &result,
-        &JsValue::from_str("sent"),
-        &JsValue::from_bool(sent),
-    )?;
-    js_sys::Reflect::set(
-        &result,
-        &JsValue::from_str("collapsedSpans"),
-        &JsValue::from_f64(collapsed_spans as f64),
-    )?;
-    Ok(result.into())
-}
-
 #[wasm_bindgen]
 impl WasmSpanState {
     #[wasm_bindgen(constructor)]
@@ -268,8 +250,7 @@ impl WasmSpanState {
             .set_language_interpreter(lang_interpreter)
             .set_otlp_instrumentation_scope("dd-trace-js", tracer_version)
             // Populate the payload-level TracerMetadata (service/env/hostname/
-            // app_version) the agent receives. These values are already passed
-            // in for the stats collector; without these calls the trace
+            // app_version) the agent receives. Without these calls the trace
             // payload's tracer metadata is sent empty.
             .set_service(tracer_service)
             .set_env(env)
@@ -278,16 +259,18 @@ impl WasmSpanState {
             .set_runtime_id(runtime_id)
             .enable_agent_rates_payload_version();
 
-        // Advertise `Datadog-Client-Computed-Stats` so the agent skips its own
-        // APM stats/sampling for these traces. This is required in two cases:
-        //  - `stats_enabled`: we build a StatsCollector and send client-side
-        //    stats, so the agent MUST NOT also compute them (double counting);
-        //  - `client_computed_stats`: set independently for APM-standalone
-        //    (apmTracingEnabled=false), where the agent should skip APM stats
-        //    even though we don't compute them client-side.
-        // Enabling stats therefore always implies the header, so OR the flags
-        // rather than relying on the caller to keep them in sync.
-        if client_computed_stats || stats_enabled {
+        // Client-side stats. Two disjoint modes:
+        //  - `stats_enabled`: libdatadog runs the concentrator + /v0.6/stats
+        //    worker natively (LocalRuntime::spawn_worker), gates activation on
+        //    the agent's /info (`client_drop_p0s` + `/v0.6/stats`), and stamps
+        //    `Datadog-Client-Computed-Stats` per trace request when stats
+        //    actually run.
+        //  - `client_computed_stats` (without `stats_enabled`): APM-standalone
+        //    (apmTracingEnabled=false). We advertise the header so the agent
+        //    skips its own APM stats, even though we don't compute any here.
+        if stats_enabled {
+            builder.enable_stats(Duration::from_secs(10));
+        } else if client_computed_stats {
             builder.set_client_computed_stats();
         }
 
@@ -311,31 +294,12 @@ impl WasmSpanState {
             pid,
         );
 
-        let stats_collector = if stats_enabled {
-            Some(stats::StatsCollector::new(
-                Duration::from_secs(10),
-                url.to_string(),
-                stats::StatsMeta {
-                    hostname: hostname.to_string(),
-                    env: env.to_string(),
-                    version: app_version.to_string(),
-                    lang: lang.to_string(),
-                    tracer_version: tracer_version.to_string(),
-                    runtime_id: runtime_id.to_string(),
-                    service: tracer_service.to_string(),
-                },
-            ))
-        } else {
-            None
-        };
-
         Ok(WasmSpanState {
             change_queue,
             string_table_input: vec![0u8; string_table_input_size as usize],
             exporter: UnsafeCell::new(None),
             builder: UnsafeCell::new(Some(builder)),
             cbs: RefCell::new(change_buffer_state),
-            stats_collector: RefCell::new(stats_collector),
             prepared_spans: RefCell::new(Vec::new()),
             sending: Cell::new(false),
             use_v05: Cell::new(false),
@@ -439,8 +403,8 @@ impl WasmSpanState {
         self.string_table_input.len() as u32
     }
 
-    /// Prepare a chunk of spans for sending. Flushes the change buffer,
-    /// extracts spans, feeds stats. Returns `true` if a chunk was prepared
+    /// Prepare a chunk of spans for sending. Flushes the change buffer and
+    /// extracts spans. Returns `true` if a chunk was prepared
     /// (there are spans to send) and `false` if there was nothing to send.
     /// Must be followed by `sendPreparedChunk()` to actually send.
     #[wasm_bindgen(js_name = "prepareChunk")]
@@ -486,10 +450,6 @@ impl WasmSpanState {
             .flush_chunk(&span_ids, first_is_local_root)
             .map_err(|e| JsValue::from_str(&e.to_string()))?;
 
-        if let Some(collector) = self.stats_collector.borrow_mut().as_mut() {
-            collector.add_spans(&spans_vec);
-        }
-
         // Stage this trace's chunk for the subsequent sendPreparedChunk call.
         // Multiple prepareChunk calls (one per trace) accumulate here and are
         // sent together as one multi-trace request. An empty result (e.g. every
@@ -590,43 +550,6 @@ impl WasmSpanState {
             .map_err(|e| JsValue::from_str(&format!("{:?}", e)))
     }
 
-    /// Flush aggregated stats to the agent's /v0.6/stats endpoint.
-    ///
-    /// Should be called periodically (e.g. every 10s) from JS, and with
-    /// `force=true` on shutdown. Returns `{ sent, collapsedSpans }` so JS can
-    /// emit the same collapsed-span health metric as libdd-trace-stats's native
-    /// exporter.
-    #[wasm_bindgen(js_name = "flushStats")]
-    pub async fn flush_stats(&self, force: bool) -> Result<JsValue, JsValue> {
-        // Build the stats request under a brief *synchronous* borrow, then drop
-        // the borrow BEFORE the async send. The collector therefore stays in
-        // `stats_collector`, so a concurrent `prepareChunk` during the in-flight
-        // send still reaches `add_spans` and those spans are counted. (Taking
-        // the collector out for the whole await would silently drop them from
-        // client-side stats.) No borrow is held across the await, so there is
-        // no double-borrow hazard from overlapping calls.
-        let prepared = {
-            let mut guard = self.stats_collector.borrow_mut();
-            match guard.as_mut() {
-                Some(collector) => collector
-                    .prepare_request(force)
-                    .map_err(|e| JsValue::from_str(&e))?,
-                None => return stats_flush_result(false, 0),
-            }
-        };
-        let sent = match prepared.request {
-            Some(req) => {
-                stats::StatsCollector::send_request(req)
-                    .await
-                    .map_err(|e| JsValue::from_str(&e))?;
-                true
-            }
-            None => false,
-        };
-
-        stats_flush_result(sent, prepared.collapsed_spans)
-    }
-
     /// Flush the queued change-buffer operations. On success always returns
     /// `true` (the bool exists only for signature symmetry with the other
     /// flush methods); failures surface as a thrown error.
diff --git a/crates/pipeline/src/stats.rs b/crates/pipeline/src/stats.rs
deleted file mode 100644
index 3e65cb46..00000000
--- a/crates/pipeline/src/stats.rs
+++ /dev/null
@@ -1,201 +0,0 @@
-// Copyright 2026-Present Datadog, Inc. https://www.datadoghq.com/
-// SPDX-License-Identifier: Apache-2.0
-
-//! Native stats collection for the pipeline WASM module.
-//!
-//! Wraps `SpanConcentrator` from `libdd-trace-stats` and provides encoding +
-//! HTTP transport for flushing stats to the Datadog agent's `/v0.6/stats`
-//! endpoint.
-
-use web_time::{Duration, SystemTime};
-
-/// Wall-clock now() for wasm. Delegates to `web_time::SystemTime::now()`,
-/// which routes to JS `Date.now()` on `wasm32-unknown-unknown` (native
-/// `std::time::SystemTime::now()` is unimplemented on that target and traps).
-fn now() -> SystemTime {
-    SystemTime::now()
-}
-
-use bytes::Bytes;
-use libdatadog_nodejs_capabilities::WasmHttpClient;
-use libdd_capabilities::http::HttpClientCapability;
-use libdd_common::parse_uri;
-use libdd_trace_protobuf::pb;
-use libdd_trace_stats::span_concentrator::SpanConcentrator;
-
-use crate::trace_data::WasmTraceData;
-
-const STATS_ENDPOINT_PATH: &str = "/v0.6/stats";
-
-/// Metadata for the stats payload envelope.
-pub struct StatsMeta {
-    pub hostname: String,
-    pub env: String,
-    pub version: String,
-    pub lang: String,
-    pub tracer_version: String,
-    pub runtime_id: String,
-    pub service: String,
-}
-
-/// Stats data prepared by a synchronous concentrator flush.
-pub struct PreparedStatsFlush {
-    pub request: Option<http::Request<Bytes>>,
-    pub collapsed_spans: u64,
-}
-
-/// Manages stats aggregation and flushing.
-pub struct StatsCollector {
-    concentrator: SpanConcentrator,
-    meta: StatsMeta,
-    agent_url: String,
-    sequence: u64,
-}
-
-impl StatsCollector {
-    /// Create a new stats collector.
-    pub fn new(bucket_size: Duration, agent_url: String, meta: StatsMeta) -> Self {
-        StatsCollector {
-            concentrator: SpanConcentrator::new(
-                bucket_size,
-                now(),
-                vec![
-                    "client".to_string(),
-                    "server".to_string(),
-                    "producer".to_string(),
-                    "consumer".to_string(),
-                ],
-                Vec::new(),
-                None,
-                Vec::new(),
-            ),
-            meta,
-            agent_url,
-            sequence: 0,
-        }
-    }
-
-    /// Add spans to the concentrator for stats aggregation.
-    ///
-    /// The spans should already have `_dd.top_level` and `_dd.measured` metrics
-    /// set (done by `ChangeBufferState::flush_chunk`).
-    pub fn add_spans(&mut self, spans: &[libdd_trace_utils::span::v04::Span<WasmTraceData>]) {
-        for span in spans {
-            self.concentrator.add_span(span);
-        }
-    }
-
-    /// Drain aggregated stats into a ready-to-send request plus flush metadata,
-    /// **synchronously**.
-    ///
-    /// Returns `request: None` when there is no stats payload to send. The
-    /// concentrator is drained and the sequence advanced as part of this call,
-    /// so a returned request must be sent (see `send_request`). Kept
-    /// synchronous and separate from the send so a caller can build the request
-    /// under a brief borrow and release the collector *before* the async send —
-    /// leaving it available for `add_spans` while the stats request is in
-    /// flight.
-    pub fn prepare_request(&mut self, force: bool) -> Result<PreparedStatsFlush, String> {
-        let mut flush = self.concentrator.flush(now(), force);
-        let collapsed_spans = flush.collapsed_spans;
-        if !flush.obfuscated_buckets.is_empty() {
-            // TODO: stats obfuscation is currently disabled. Obfuscated stats
-            // require the datadog-obfuscation-version header, which
-            // prepare_request doesn't emit yet. Add that header before enabling
-            // stats-obfuscation.
-            return Err(
-                "stats flush produced obfuscated buckets without obfuscation header support"
-                    .to_string(),
-            );
-        }
-        if flush.unobfuscated_buckets.is_empty() {
-            return Ok(PreparedStatsFlush {
-                request: None,
-                collapsed_spans,
-            });
-        }
-
-        self.sequence += 1;
-        let buckets = std::mem::take(&mut flush.unobfuscated_buckets);
-        let payload = encode_stats_payload(&buckets, &self.meta, self.sequence);
-
-        let body = rmp_serde::encode::to_vec_named(&payload)
-            .map_err(|e| format!("stats msgpack encode error: {e}"))?;
-
-        // Build the base agent URI exactly like the trace exporter does, via
-        // libdatadog's `parse_uri`. For a `unix://` / `windows:` agent URL that
-        // hex-encodes the socket path into the URI *authority* (there is no
-        // standard URL form for socket paths), which the WASM HTTP client's
-        // `decode_socket_path` reverses to route over the socket. A raw parse
-        // instead leaves the socket path in the URI *path* with an empty/invalid
-        // authority, so the stats request never reaches the socket — client stats
-        // silently never arrive over UDS (dd-trace-js #9139, uds-express4).
-        let base = parse_uri(&self.agent_url).map_err(|e| format!("invalid agent URL: {e}"))?;
-        // Append `/v0.6/stats` to the base path while preserving the (hex)
-        // authority, mirroring libdd-data-pipeline's `add_path`. For `unix://`
-        // the base path is "/" and the authority holds the hex socket path; for
-        // TCP it's `http://host:port/`. Trim a trailing slash so the path is
-        // exactly `/v0.6/stats` (a double slash makes the agent miss the request).
-        let base_path = base.path().strip_suffix('/').unwrap_or_else(|| base.path());
-        let new_path_and_query = format!("{base_path}{STATS_ENDPOINT_PATH}");
-        let mut parts = base.into_parts();
-        parts.path_and_query = Some(
-            new_path_and_query
-                .parse()
-                .map_err(|e| format!("invalid stats path: {e}"))?,
-        );
-        let uri = http::Uri::from_parts(parts).map_err(|e| format!("invalid stats URL: {e}"))?;
-
-        let req = http::Request::builder()
-            .method(http::Method::PUT)
-            .uri(uri)
-            .header("Content-Type", "application/msgpack")
-            .header("Datadog-Meta-Lang", &self.meta.lang)
-            .header("Datadog-Meta-Tracer-Version", &self.meta.tracer_version)
-            .body(Bytes::from(body))
-            .map_err(|e| format!("failed to build stats request: {e}"))?;
-
-        Ok(PreparedStatsFlush {
-            request: Some(req),
-            collapsed_spans,
-        })
-    }
-
-    /// Send a prepared stats request to the agent. Does **not** borrow the
-    /// collector, so trace export (`add_spans`) can proceed during the await.
-    pub async fn send_request(req: http::Request<Bytes>) -> Result<(), String> {
-        let client = WasmHttpClient::new_client();
-        client
-            .request(req)
-            .await
-            .map_err(|e| format!("stats send error: {e:?}"))?;
-        Ok(())
-    }
-}
-
-/// Encode flushed stats buckets into a `ClientStatsPayload` for msgpack
-/// serialization.
-fn encode_stats_payload(
-    buckets: &[pb::ClientStatsBucket],
-    meta: &StatsMeta,
-    sequence: u64,
-) -> pb::ClientStatsPayload {
-    pb::ClientStatsPayload {
-        hostname: meta.hostname.clone(),
-        env: meta.env.clone(),
-        version: meta.version.clone(),
-        lang: meta.lang.clone(),
-        tracer_version: meta.tracer_version.clone(),
-        runtime_id: meta.runtime_id.clone(),
-        sequence,
-        stats: buckets.to_vec(),
-        service: meta.service.clone(),
-        container_id: String::new(),
-        tags: Vec::new(),
-        agent_aggregation: String::new(),
-        git_commit_sha: String::new(),
-        image_tag: String::new(),
-        process_tags: String::new(),
-        process_tags_hash: 0,
-    }
-}
diff --git a/test/pipeline.js b/test/pipeline.js
index 59511fef..7089e81f 100644
--- a/test/pipeline.js
+++ b/test/pipeline.js
@@ -1081,171 +1081,10 @@ describe('pipeline', { skip }, () => {
       assert.strictEqual(header, undefined)
     })
 
-    it('sends the header when stats are enabled (client-side stats imply it)', async () => {
-      // Enabling client-side stats without clientComputedStats must still send
-      // the header, otherwise the agent double-counts APM stats.
-      const { header, sawTraces } = await captureTraceHeader({ statsEnabled: true, clientComputedStats: false })
-      assert.ok(sawTraces, 'expected a POST to /v0.4/traces')
-      assert.strictEqual(header, 'true')
-    })
-  })
-
-  describe('client-side stats', () => {
-    it('aggregates and flushes stats to /v0.6/stats', async () => {
-      const http = require('node:http')
-      const seen = []
-      const server = http.createServer((req, res) => {
-        const chunks = []
-        req.on('data', c => chunks.push(c))
-        req.on('end', () => {
-          seen.push({ method: req.method, url: req.url, len: Buffer.concat(chunks).length })
-          res.writeHead(200, { 'content-type': 'application/json' })
-          res.end('{}')
-        })
-      })
-      await new Promise(resolve => server.listen(0, '127.0.0.1', resolve))
-      const { port } = server.address()
-
-      // statsEnabled:true builds the StatsCollector; prepareChunk feeds spans
-      // into it, and flushStats(true) force-flushes to /v0.6/stats.
-      const ns = new NativeSpansInterface({ agentUrl: `http://127.0.0.1:${port}`, statsEnabled: true })
-      const span = ns.createSpan()
-      span.name = 'stats-span'
-      span.service = 'stats-svc'
-      span.resource = '/stats'
-      span.type = 'web'
-      span.duration = 5_000_000n
-
-      try {
-        await ns.flushSpans(span)
-        const result = await ns.state.flushStats(true)
-        assert.deepStrictEqual(result, { sent: true, collapsedSpans: 0 }, 'flushStats reported a send')
-        const statsReq = seen.find(r => r.url === '/v0.6/stats')
-        assert.ok(statsReq, 'agent received a /v0.6/stats request')
-        assert.strictEqual(statsReq.method, 'PUT')
-        assert.ok(statsReq.len > 0, 'stats payload is non-empty')
-
-        // Nothing new aggregated -> a second forced flush is a no-op.
-        assert.deepStrictEqual(await ns.state.flushStats(true), { sent: false, collapsedSpans: 0 }, 'second flush has nothing to send')
-      } finally {
-        server.closeAllConnections?.()
-        server.close()
-      }
-    })
-
-    it('returns collapsed span count when stats cardinality overflows', async () => {
-      const http = require('node:http')
-      const seen = []
-      const server = http.createServer((req, res) => {
-        const chunks = []
-        req.on('data', c => chunks.push(c))
-        req.on('end', () => {
-          seen.push({ method: req.method, url: req.url, len: Buffer.concat(chunks).length })
-          res.writeHead(200, { 'content-type': 'application/json' })
-          res.end('{}')
-        })
-      })
-      await new Promise(resolve => server.listen(0, '127.0.0.1', resolve))
-      const { port } = server.address()
-
-      const ns = new NativeSpansInterface({ agentUrl: `http://127.0.0.1:${port}`, statsEnabled: true })
-      let batch = []
-
-      try {
-        for (let i = 0; i < 15_000; i++) {
-          const span = ns.createSpan()
-          span.name = 'stats-span'
-          span.service = 'stats-svc'
-          span.resource = `/stats/${i}`
-          span.type = 'web'
-          span.setTag('span.kind', 'server')
-          span.duration = 5_000_000n
-          ns.flushChangeQueue()
-          batch.push(span)
-          if (batch.length === 500) {
-            await ns.flushSpans(...batch)
-            batch = []
-          }
-        }
-        if (batch.length > 0) {
-          await ns.flushSpans(...batch)
-        }
-
-        const result = await ns.state.flushStats(true)
-        assert.strictEqual(result.sent, true)
-        assert.ok(result.collapsedSpans > 0, 'stats cardinality overflow reported collapsed spans')
-        assert.ok(seen.some(r => r.url === '/v0.6/stats'), 'agent received a /v0.6/stats request')
-      } finally {
-        server.closeAllConnections?.()
-        server.close()
-      }
-    })
-
-    it('flushStats reports no send when stats are disabled', async () => {
-      const ns = new NativeSpansInterface({ statsEnabled: false })
-      assert.deepStrictEqual(await ns.state.flushStats(true), { sent: false, collapsedSpans: 0 })
-    })
-
-    it('flushes stats to /v0.6/stats over a Unix domain socket', { skip: process.platform === 'win32' }, async () => {
-      // A `unix://` agent URL must route /v0.6/stats over the socket, like
-      // traces do. parse_uri hex-encodes the socket path into the URI authority
-      // (which the transport's decode_socket_path reverses); a raw parse would
-      // leave the path in the URI path and never reach the socket.
-      const http = require('node:http')
-      const os = require('node:os')
-      const fs = require('node:fs')
-      const nodePath = require('node:path')
-      // Keep the path short — AF_UNIX paths are capped (~104 bytes on macOS).
-      const sockPath = nodePath.join(os.tmpdir(), `dd-st-${process.pid}.sock`)
-      try {
-        fs.unlinkSync(sockPath)
-      } catch {
-        // not present
-      }
-      const seen = []
-      const server = http.createServer((req, res) => {
-        const chunks = []
-        req.on('data', c => chunks.push(c))
-        req.on('end', () => {
-          seen.push({ method: req.method, url: req.url, len: Buffer.concat(chunks).length })
-          res.writeHead(200, { 'content-type': 'application/json' })
-          res.end('{}')
-        })
-      })
-      await new Promise((resolve, reject) => {
-        server.once('error', reject)
-        server.listen(sockPath, resolve)
-      })
-
-      const ns = new NativeSpansInterface({ agentUrl: `unix://${sockPath}`, statsEnabled: true })
-      const span = ns.createSpan()
-      span.name = 'stats-span'
-      span.service = 'stats-svc'
-      span.resource = '/stats'
-      span.type = 'web'
-      span.duration = 5_000_000n
-
-      try {
-        await ns.flushSpans(span)
-        const result = await ns.state.flushStats(true)
-        assert.deepStrictEqual(
-          result,
-          { sent: true, collapsedSpans: 0 },
-          'flushStats reported a send over the socket',
-        )
-        const statsReq = seen.find(r => r.url === '/v0.6/stats')
-        assert.ok(statsReq, 'agent received a /v0.6/stats request over the socket')
-        assert.ok(statsReq.len > 0, 'stats payload is non-empty')
-      } finally {
-        server.closeAllConnections?.()
-        server.close()
-        try {
-          fs.unlinkSync(sockPath)
-        } catch {
-          // already gone
-        }
-      }
-    })
+    // When statsEnabled=true, libdatadog stamps the header dynamically only
+    // after the agent /info advertises `client_drop_p0s` + `/v0.6/stats`.
+    // That's inherently race-y in a unit test, so it's covered end-to-end
+    // instead of asserted here.
   })
 
   describe('send re-entrancy', () => {

From 724fab9a9a00338eb66aa7b0187fab98f1245008 Mon Sep 17 00:00:00 2001
From: Jules Wiriath <jules.wiriath@datadoghq.com>
Date: Fri, 24 Jul 2026 16:48:01 +0200
Subject: [PATCH 5/6] feat: added force shutdown binding, and trimmed out
 verbose comments

---
 crates/pipeline/src/lib.rs | 49 ++++++++++++++++++++++++++++----------
 test/pipeline.js           |  5 ----
 2 files changed, 37 insertions(+), 17 deletions(-)

diff --git a/crates/pipeline/src/lib.rs b/crates/pipeline/src/lib.rs
index 1fb05c45..2ddddd09 100644
--- a/crates/pipeline/src/lib.rs
+++ b/crates/pipeline/src/lib.rs
@@ -249,9 +249,7 @@ impl WasmSpanState {
             .set_language_version(lang_version)
             .set_language_interpreter(lang_interpreter)
             .set_otlp_instrumentation_scope("dd-trace-js", tracer_version)
-            // Populate the payload-level TracerMetadata (service/env/hostname/
-            // app_version) the agent receives. Without these calls the trace
-            // payload's tracer metadata is sent empty.
+            // Without these setters the payload-level TracerMetadata is empty.
             .set_service(tracer_service)
             .set_env(env)
             .set_hostname(hostname)
@@ -259,15 +257,11 @@ impl WasmSpanState {
             .set_runtime_id(runtime_id)
             .enable_agent_rates_payload_version();
 
-        // Client-side stats. Two disjoint modes:
-        //  - `stats_enabled`: libdatadog runs the concentrator + /v0.6/stats
-        //    worker natively (LocalRuntime::spawn_worker), gates activation on
-        //    the agent's /info (`client_drop_p0s` + `/v0.6/stats`), and stamps
-        //    `Datadog-Client-Computed-Stats` per trace request when stats
-        //    actually run.
-        //  - `client_computed_stats` (without `stats_enabled`): APM-standalone
-        //    (apmTracingEnabled=false). We advertise the header so the agent
-        //    skips its own APM stats, even though we don't compute any here.
+        // `enable_stats` makes libdatadog stamp the client-computed-stats
+        // header itself when stats run, so the two flags are disjoint:
+        // `set_client_computed_stats` is only for APM-standalone
+        // (`apmTracingEnabled=false`), where the header is advertised
+        // without any stats actually being computed.
         if stats_enabled {
             builder.enable_stats(Duration::from_secs(10));
         } else if client_computed_stats {
@@ -562,6 +556,37 @@ impl WasmSpanState {
         Ok(true)
     }
 
+    /// Force-flush the current stats bucket and stop the background workers.
+    /// The stats worker only flushes on its bucket interval, so spans
+    /// recorded between the last tick and process exit are lost unless this
+    /// is awaited during tracer shutdown. Consumes the exporter — subsequent
+    /// sends will error.
+    ///
+    /// `timeoutMs` bounds the wait; on timeout returns an error and workers
+    /// may still be finishing. `None` waits indefinitely.
+    #[wasm_bindgen(js_name = "shutdown")]
+    pub async fn shutdown(&self, timeout_ms: Option<u32>) -> Result<(), JsValue> {
+        // `sendPreparedChunk` holds an `&mut` on the exporter across awaits;
+        // taking it out from under an in-flight send would alias.
+        if self.sending.get() {
+            return Err(JsValue::from_str("shutdown: sendPreparedChunk in flight"));
+        }
+        self.sending.set(true);
+        let _in_flight = InFlightGuard(&self.sending);
+
+        // SAFETY: `sending` guard prevents overlapping access; WASM is single-threaded.
+        let exporter_slot = unsafe { &mut *self.exporter.get() };
+        // Idempotent: never-built or already-shut-down state is not an error.
+        let Some(exporter) = exporter_slot.take() else {
+            return Ok(());
+        };
+        let timeout = timeout_ms.map(|ms| Duration::from_millis(u64::from(ms)));
+        exporter
+            .shutdown_async(timeout)
+            .await
+            .map_err(|e| JsValue::from_str(&format!("shutdown: {e:?}")))
+    }
+
     /// Set default meta tags applied to every new span.
     /// Takes a flat array of key-value pairs: [key1, val1, key2, val2, ...]
     #[wasm_bindgen(js_name = "setDefaultMeta")]
diff --git a/test/pipeline.js b/test/pipeline.js
index 7089e81f..08032c07 100644
--- a/test/pipeline.js
+++ b/test/pipeline.js
@@ -1080,11 +1080,6 @@ describe('pipeline', { skip }, () => {
       assert.ok(sawTraces, 'expected a POST to /v0.4/traces')
       assert.strictEqual(header, undefined)
     })
-
-    // When statsEnabled=true, libdatadog stamps the header dynamically only
-    // after the agent /info advertises `client_drop_p0s` + `/v0.6/stats`.
-    // That's inherently race-y in a unit test, so it's covered end-to-end
-    // instead of asserted here.
   })
 
   describe('send re-entrancy', () => {

From 29f55b11943990a7671a27784f3fcae096af275f Mon Sep 17 00:00:00 2001
From: Jules Wiriath <jules.wiriath@datadoghq.com>
Date: Mon, 27 Jul 2026 12:16:12 +0200
Subject: [PATCH 6/6] docs: fix

---
 Cargo.lock                     | 87 ++++++++++++++++++++++------------
 crates/capabilities/Cargo.toml |  2 +-
 crates/pipeline/src/lib.rs     |  8 ++--
 3 files changed, 60 insertions(+), 37 deletions(-)

diff --git a/Cargo.lock b/Cargo.lock
index 0cda1f3b..5aa7b6bf 100644
--- a/Cargo.lock
+++ b/Cargo.lock
@@ -1031,7 +1031,7 @@ dependencies = [
  "libc",
  "libdd-common 5.0.0",
  "libdd-libunwind-sys",
- "libdd-telemetry",
+ "libdd-telemetry 5.0.1",
  "nix 0.29.0",
  "num-derive",
  "num-traits",
@@ -1067,12 +1067,13 @@ dependencies = [
  "libdd-capabilities 2.1.0",
  "libdd-capabilities-impl 3.0.0",
  "libdd-common 5.1.0",
- "libdd-ddsketch 1.1.0",
+ "libdd-ddsketch 1.1.0 (git+https://github.com/DataDog/libdatadog.git?rev=15899dfe754d12186ce7db72f0ff41c1920d52ec)",
  "libdd-dogstatsd-client",
  "libdd-shared-runtime 2.0.0",
+ "libdd-telemetry 6.0.0",
  "libdd-tinybytes",
  "libdd-trace-normalization",
- "libdd-trace-protobuf 4.0.0",
+ "libdd-trace-protobuf 4.0.0 (git+https://github.com/DataDog/libdatadog.git?rev=15899dfe754d12186ce7db72f0ff41c1920d52ec)",
  "libdd-trace-stats",
  "libdd-trace-utils",
  "rmp-serde",
@@ -1102,6 +1103,14 @@ dependencies = [
  "prost",
 ]
 
+[[package]]
+name = "libdd-ddsketch"
+version = "1.1.0"
+source = "git+https://github.com/DataDog/libdatadog.git?rev=3081603d3c74f209be4e3be951f78a1a7469397f#3081603d3c74f209be4e3be951f78a1a7469397f"
+dependencies = [
+ "prost",
+]
+
 [[package]]
 name = "libdd-dogstatsd-client"
 version = "4.0.0"
@@ -1120,26 +1129,12 @@ dependencies = [
 
 [[package]]
 name = "libdd-library-config"
-version = "1.0.0"
-source = "git+https://github.com/DataDog/libdatadog.git?rev=353134770b312b7ccd2df6afabc253090b948e5f#353134770b312b7ccd2df6afabc253090b948e5f"
-dependencies = [
- "anyhow",
- "memfd",
- "rand",
- "rmp",
- "rmp-serde",
- "serde",
- "serde_yaml",
-]
-
-[[package]]
-name = "libdd-library-config"
-version = "2.0.0"
-source = "git+https://github.com/DataDog/libdatadog.git?rev=7cdeb7896e92d1ba38bde495934e112dac2eda25#7cdeb7896e92d1ba38bde495934e112dac2eda25"
+version = "3.0.0"
+source = "git+https://github.com/DataDog/libdatadog.git?rev=0c6e2a5df2a163d34c4f385353ffc5d7257c72f4#0c6e2a5df2a163d34c4f385353ffc5d7257c72f4"
 dependencies = [
  "anyhow",
  "libc",
- "libdd-trace-protobuf 3.0.2",
+ "libdd-trace-protobuf 4.0.0 (git+https://github.com/DataDog/libdatadog.git?rev=0c6e2a5df2a163d34c4f385353ffc5d7257c72f4)",
  "memfd",
  "prost",
  "rand",
@@ -1221,6 +1216,35 @@ dependencies = [
  "winver",
 ]
 
+[[package]]
+name = "libdd-telemetry"
+version = "6.0.0"
+source = "git+https://github.com/DataDog/libdatadog.git?rev=15899dfe754d12186ce7db72f0ff41c1920d52ec#15899dfe754d12186ce7db72f0ff41c1920d52ec"
+dependencies = [
+ "anyhow",
+ "async-trait",
+ "base64",
+ "bytes",
+ "futures",
+ "getrandom 0.2.17",
+ "hashbrown 0.15.5",
+ "http",
+ "libc",
+ "libdd-capabilities 2.1.0",
+ "libdd-common 5.1.0",
+ "libdd-ddsketch 1.1.0 (git+https://github.com/DataDog/libdatadog.git?rev=15899dfe754d12186ce7db72f0ff41c1920d52ec)",
+ "libdd-shared-runtime 2.0.0",
+ "serde",
+ "serde_json",
+ "sys-info",
+ "tokio",
+ "tokio-util",
+ "tracing",
+ "uuid",
+ "web-time",
+ "winver",
+]
+
 [[package]]
 name = "libdd-tinybytes"
 version = "1.1.1"
@@ -1235,7 +1259,7 @@ version = "3.0.0"
 source = "git+https://github.com/DataDog/libdatadog.git?rev=15899dfe754d12186ce7db72f0ff41c1920d52ec#15899dfe754d12186ce7db72f0ff41c1920d52ec"
 dependencies = [
  "anyhow",
- "libdd-trace-protobuf 4.0.0",
+ "libdd-trace-protobuf 4.0.0 (git+https://github.com/DataDog/libdatadog.git?rev=15899dfe754d12186ce7db72f0ff41c1920d52ec)",
 ]
 
 [[package]]
@@ -1246,7 +1270,7 @@ dependencies = [
  "anyhow",
  "fluent-uri",
  "libdd-common 5.1.0",
- "libdd-trace-protobuf 4.0.0",
+ "libdd-trace-protobuf 4.0.0 (git+https://github.com/DataDog/libdatadog.git?rev=15899dfe754d12186ce7db72f0ff41c1920d52ec)",
  "libdd-trace-utils",
  "log",
  "percent-encoding",
@@ -1256,8 +1280,8 @@ dependencies = [
 
 [[package]]
 name = "libdd-trace-protobuf"
-version = "3.0.2"
-source = "git+https://github.com/DataDog/libdatadog.git?rev=7cdeb7896e92d1ba38bde495934e112dac2eda25#7cdeb7896e92d1ba38bde495934e112dac2eda25"
+version = "4.0.0"
+source = "git+https://github.com/DataDog/libdatadog.git?rev=0c6e2a5df2a163d34c4f385353ffc5d7257c72f4#0c6e2a5df2a163d34c4f385353ffc5d7257c72f4"
 dependencies = [
  "prost",
  "serde",
@@ -1288,11 +1312,12 @@ dependencies = [
  "libdd-capabilities 2.1.0",
  "libdd-capabilities-impl 3.0.0",
  "libdd-common 5.1.0",
- "libdd-ddsketch 1.1.0",
+ "libdd-ddsketch 1.1.0 (git+https://github.com/DataDog/libdatadog.git?rev=15899dfe754d12186ce7db72f0ff41c1920d52ec)",
  "libdd-dogstatsd-client",
  "libdd-shared-runtime 2.0.0",
+ "libdd-telemetry 6.0.0",
  "libdd-trace-obfuscation",
- "libdd-trace-protobuf 4.0.0",
+ "libdd-trace-protobuf 4.0.0 (git+https://github.com/DataDog/libdatadog.git?rev=15899dfe754d12186ce7db72f0ff41c1920d52ec)",
  "libdd-trace-utils",
  "rmp-serde",
  "serde",
@@ -1323,7 +1348,7 @@ dependencies = [
  "libdd-common 5.1.0",
  "libdd-tinybytes",
  "libdd-trace-normalization",
- "libdd-trace-protobuf 4.0.0",
+ "libdd-trace-protobuf 4.0.0 (git+https://github.com/DataDog/libdatadog.git?rev=15899dfe754d12186ce7db72f0ff41c1920d52ec)",
  "prost",
  "rand",
  "rmp",
@@ -1360,7 +1385,7 @@ version = "0.2.0"
 dependencies = [
  "anyhow",
  "getrandom 0.2.17",
- "libdd-library-config 1.0.0",
+ "libdd-library-config",
  "serde",
  "serde-wasm-bindgen",
  "wasm-bindgen",
@@ -1869,8 +1894,8 @@ name = "process-discovery"
 version = "0.1.0"
 dependencies = [
  "anyhow",
- "libdd-library-config 2.0.0",
- "libdd-trace-protobuf 3.0.2",
+ "libdd-library-config",
+ "libdd-trace-protobuf 4.0.0 (git+https://github.com/DataDog/libdatadog.git?rev=0c6e2a5df2a163d34c4f385353ffc5d7257c72f4)",
  "napi",
  "napi-derive",
 ]
@@ -2348,7 +2373,7 @@ checksum = "703d5c7ef118737c72f1af64ad2f6f8c5e1921f818cdcb97b8fe6fc69bf66214"
 name = "sketches"
 version = "0.1.0"
 dependencies = [
- "libdd-ddsketch 1.1.0",
+ "libdd-ddsketch 1.1.0 (git+https://github.com/DataDog/libdatadog.git?rev=3081603d3c74f209be4e3be951f78a1a7469397f)",
  "wasm-bindgen",
 ]
 
diff --git a/crates/capabilities/Cargo.toml b/crates/capabilities/Cargo.toml
index edb40adc..371b3f4c 100644
--- a/crates/capabilities/Cargo.toml
+++ b/crates/capabilities/Cargo.toml
@@ -15,7 +15,7 @@ http = "1"
 bytes = "1.4"
 futures-core = "0.3"
 anyhow = "1"
-libdd-capabilities = { git = "https://github.com/DataDog/libdatadog.git", rev = "3081603d3c74f209be4e3be951f78a1a7469397f" }
+libdd-capabilities = { git = "https://github.com/DataDog/libdatadog.git", rev = "15899dfe754d12186ce7db72f0ff41c1920d52ec" }
 
 [dev-dependencies]
 wasm-bindgen-test = "0.3"
diff --git a/crates/pipeline/src/lib.rs b/crates/pipeline/src/lib.rs
index 2ddddd09..b3108f15 100644
--- a/crates/pipeline/src/lib.rs
+++ b/crates/pipeline/src/lib.rs
@@ -556,11 +556,9 @@ impl WasmSpanState {
         Ok(true)
     }
 
-    /// Force-flush the current stats bucket and stop the background workers.
-    /// The stats worker only flushes on its bucket interval, so spans
-    /// recorded between the last tick and process exit are lost unless this
-    /// is awaited during tracer shutdown. Consumes the exporter — subsequent
-    /// sends will error.
+    /// Gracefully shut down the exporter and stop the background workers.
+    /// Should be awaited during tracer shutdown to avoid losing in-flight
+    /// data. Consumes the exporter — subsequent sends will error.
     ///
     /// `timeoutMs` bounds the wait; on timeout returns an error and workers
     /// may still be finishing. `None` waits indefinitely.